IUCN threat status:

Distribution

New Zealand mudsnails (Potamopyrgus antipodarum) are native to freshwater streams and lakes of New Zealand and small, neighboring islands. However, by several speculated means of human introduction, they have become an invasive species in Australia, Europe, and North America. Occurrences of the species in North America, most of which are in the western United States, have been carefully documented since it was first discovered in Idaho. The snails are known to be established in Oregon, California, northern Arizona, New York, and Canada, affecting major freshwater systems such as Lake Ontario, Lake Erie, and Lake Superior. They also have been recently introduced in Japan.